In response to the Validation of Pediatric Patient Reported Outcomes in Chronic Diseases (PEPR) Consortium RFA, we propose to create the Child-Centered Outcomes in Practice and Research (COPR) Center of Excellence. The purpose of COPR is to strengthen the clinical validity of PROMIS pediatric measures for children with chronic conditions. Its long-term goal is to accelerate the adoption of these measures in clinical practice and research. COPR includes three research projects that focus on pediatric Crohn's disease, chronic kidney disease, and cancer. The projects are linked by common measures, methods, and infrastructure. The clinical validity of the same four PROMIS measures?pain interference, fatigue, psychological stress experiences, and positive affect?will be evaluated for each population. The COPR Informatics and Methodology Core (IMC) will ensure consistent application of data management and statistical methodologies across the research projects. The IMC will leverage existing informatics and methodological resources including the PEDSnet Data Coordinating Center (led by PI Forrest), which manages standardized electronic health record and patient-reported data for 4.5 million children, and the PROMIS@CHOP research program, which developed 10 PROMIS Pediatric measures and includes some of the nation's leading pediatric patient- reported outcome (PRO) researchers. The IMC is supported by a panel of nationally recognized experts in informatics, content and construct validity, FDA guidance on PROs, and the clinical application of PROMIS. The IMC will: (1) leverage existing PEDSnet informatics resources to standardize data collection, storage, and sharing procedures that will maximize the security, quality, and interoperability of PROMIS datasets across the COPR research projects and with other national databases; (2) provide methodological and statistical expertise in support of COPR's research projects (e.g., clinical and construct validation methods, longitudinal data analysis, structural equation modeling); (3) investigate the need for condition-specific clinical validation by comparing and contrasting results of the COPR research studies; and, (4) improve the quality and accessibility of PROMIS instrument documentation to better facilitate FDA review and support adoption of the tools in clinical practice and research. COPR will seek FDA qualification for four PROMIS measures it is evaluating. The IMC will adopt and modify, as needed, the PEDSnet governance and operating procedures for data collection, storage, and sharing. COPR will use the PEDSnet Common Data Model (CDM), a set of standardized structures, terminologies, and rules for representing health and healthcare data that supports analyses across multiple databases collected at different times or places. Use of the CDM will render COPR data sets interoperable with one another, PEDSnet, and other national databases (e.g., PCORnet). The COPR IMC informatics, methodological, and statistical resources can be readily scaled up to support other members of the PEPR Consortium should CHOP be selected to manage the Infrastructure and Opportunities Fund.